This invention relates generally to a new method of making V-grooved pulley assembly having wall portions of different thicknesses so as to reduce the cost of materials and labor.
A V-grooved pulley assembly is normally used with electric clutches for transmitting on power of engine mounted in vehicles such as, for example, automobiles and trucks to air conditioner compressors to drive the same.
A preferable V-grooved pulley assembly is provided with a thick wall portion for the structual strength and a magnetically efficient joint which includes thin wall portions for the weight reduction.
A known V-grooved pulley assembly having portions of different thicknesses have been made by means of hot forging workings and machinings.
Problems of the known assembly are that the forging workings themselves are relatively expensive, the cost of machining same even more so, and the combination of the forging workings with the machinings reduces the operation efficiency.
To solve the above-noted problems another method has been proposed in U.S. Pat. No. 3,851,366, wherein V-belt pulley is formed from a single sheet of metal by means of bend-press workings.
Disadvantages of the known V-belt pulley structures formed from the single sheet of metal by means of bend-press working resides in the fact that the number of steps of working processes is increased and the integrity of the pulley structure is low due to the uniform thickness in any portion of the pulley structures.